Paper marking apparatus



1940- A. M. WICKWIRE. JR

PAPER MARKING APPARATUS Filed April 5, 1938 IN VENTOR.

Jr w m w a F M M no.2 A J M ATTORNEY.

Patented Mar. 5, 1940 UNITED STATES PATENT OFFICE PAPER, MARKING APPARATUS Application April 5, 1938, Serial No. 200,143

9 Claims.

This invention relates to the art of coating and marking paper where the paper is fed in webs between a marking and an impresson cylinder; and it is particularly directed to an improved press arrangement .for preventing offset or backstain on the unmarked side of the web.

In the coating and marking of certain paper, such as carton stock or stock of medium weight which is to be used subsequently in making corrugated board, it is customary to coat or-mark one side of the paper only by passing a web between an intaglio marking cylinder and a resilient impression cylinder. A doctor blade may or may not be used in conjunction with the marking cylinder, depending on the coloring or marking efiect desired. The presses used in marking this type of paper usually employ extremely long cylinders to accommodate the wide stock being colored. It is desirable to use an impression cylinder of small diameter, since the pressure required for the proper transfer of ink to the paper is more readily obtained by a cylinder of small diameter than byone of large diameter. However, the smaller the diameter of the impression cylinder is, the weaker itwillbe, so that when the pressure required for satisfactory transfer of ink is applied at the ends of the cylinder, it may result in an undesirable longitudinal bending of said cylinder. Hence, it is customary and necessary to apply the required pressure to the resilient impression'cylinder by means of a backup or pressure cylinder which is adapted to distribute the pressure throughout the length oi the impression cylinder. Efiective threading of the web, which aids in preventing warping and rippling, is then provideg by feeding the web around the surface of both the back-up and impression cylinders.

Such presses are used at present and function satisfactorily when the web width is the same as the impression cylinder used. However, it is not always possible or convenient to provide a different press or impression cylinder for each size of stock, and it often becomes necessary to run webs of a desired width through a press having rollers considerably wider than the web. When this is done, it has been found that an undesirableoffset or backstain occurs on the uncolored side of the web causing a definite waste of both paper and ink at the edge portions. v It was heretofore thought that this oirset or bacisstain was caused by the mere presence of ink on the portions of the impression cylinder extending beyond the edges of the web and contacting the ink bearing marking cylinder. Hence, all suggestions for eliminating this dimculty have involved the provision of supplementary means either for preventing the transfer of ink from the marking cylinder to the impression cylinder or for removing the ink from said exposed portions of the ima pression cylinder, or combinations of both of these means. While such systems havebeen successful to a certain degree in eliminating the dlmculty, they have not functioned efiiciently under all conditions of operation. Furthermore, such supplementary devices constitute an additional source of adjustment and trouble in the operation of the press.

I have discovered that it is possible to mark webs of difierent widths using a single press having cylinders of maximum width without the above mentioned supplementary devices and in such a manner that there will be no undesirable offset or backstain' on the uncolored side of the Web.

In accordance with my invention, this result may be accomplished by providing an improved press of the usual three roller type in which the line of contact between the back-up or pressure cylinder and the impression cylinder is interrupted in such a manner that said line of contact never overlaps the edges of the web. To do this,

I have provided a pressure cylinder having a I central web contacting portion slightly shorter than the web of minimum width, end contact portions positioned to contact the impression cylinder at points beyond the maximum width of web, and portions of reduced cross sectional area between said contacting portions. I may provide a plurality of slidable rings or collars onsaid reduced portions so that the extent of the contact portions may be increased and changed to accommodate webs of different widths and still be such that the line of contact between the pressure cylinder and the impression cylinder does not overlap the elges of the web. I

Specific embodiments of apparatus for carrying out my invention are illustrated in the accompanying drawing in which:

Figs. 1 and 2 are, respectively, front and side elevations, partly in section, of an intaglio marking press provided with my improved offset preventing pressure cylinder;

Fig. 3 is an enlarged detail view of a pressure cylinder having movable collars or rings on the reduced portions thereof; and

Fig. 4 is a vertical sectional view taken substantially along the line 4-4 of Fig. 3.

As shown in the drawing, a web it, of paper or carton stock which is to be coated, is fed from a 5 suitable and conveniently located source of supply to an intaglio printing press l2. This press, whichmay be of any suitable construction, comprises base members and side frames or standards I 6 in which is journalled an engraved or knurled marking cylinder i 8. The marking cylinder i8 may be driven at the desired speed by a motor 20 and rotates in a bath of marking material 22 contained in a fountain housing 24 which is secured by means of brackets 26 to the side frames I6. I have not shown a doctor blade or other wiping means cooperating with the marking cylinder I8, but it is to be understood that one may be used, if desired.

Mounted above the marking cylinder and driven thereby are a resilient impression cylinder 28 and a pressure or back-up cylinder 30. The pressure cylinder has each end of its shaft journalled in a slidable housing member 32, while each end of the impression cylinder shaft is rotatably mounted in a bearing block 34 which is adapted to slide up and down in a slot 36 provided in the associated housing member 32. Suitable rails or guideways 38 are provided on the side frames l6 for slidably receiving the housing members 32 which may be moved toward and away from the marking cylinder [8 by means of suitable threaded shafts 40 cooperating with internally threaded hubs 42 provided on the side frames I'6. By turning a hand wheel 44 provided on the upper end of each threaded shaft 40, the slidable housing may be moved downward or upward so as to regulate the pressure on the cylinders.

Web ID is fed in at the top of the unit over the pressure cylinder 36, then around the impression cylinder 28 to the printing or marking line. Due to the rotation of the marking cylinder in the bath 22, a quantity of the marking medium collects in the bite between the marking and impression cylinders where it is transferred to the web ill in the desired quantities as determined by the pressure employed, the depth of the intaglio markings and the presence or absence of a doctor.

As thus far described, the press construction is conventional and because of the resiliency of the impression cylinder, the portions thereof which extend beyond the edges of the web ID will contact the marking cylinder and ink will be transferred to such portions of the surface of the impression cylinder. Unless special provision is made, this ink will be transferred to the edge portions of the back of the web and cause an undesirable backstain or offset. In order to prevent this and still transmit suflicient pressure to the impression cylinder to maintain an effective transfer of ink, I have modified the construction of the usual uniformly cylindrical pressure or back-up cylinder.

As shown, the pressure cylinder 30 is not of uniform cross sectional area throughout its length but is provided with a central web contacting section or portion 46 and end contact portions 48. The central portion 46 is shown as slightly shorter than the width of the web in which is the smallest size stock that is ever marked in the press H2. The end contact portions 48 are located so that they will not contact any portion of the widest web run through the press. Thus, there are intermediate portions 50 of the cylinder, between the central portion 48 and the end contact portions 48, which-are of reduced cross sectional area and greater in length than one half the difference between the widest and narrowest webs used on the press. In this manner, the line of contact between the pressure cylinder and the impression cylinder is interrupted and will never overlap the edges of the web. I have found that this construction transmits the required pressure to the impression cylinder and effectively prevents oflset or backstain upon the encolored side of the web.

In Figs. 3 and 4, there is shown another form of improved pressure cylinder 52, which similarly to the cylinder 28, has a central web contacting portion 54, end contacting portions 56, and intermediate portions 58 of reduced cross sectional area. Preferably, however, the end contacting portions 56 are removable and the reduced sections 58 provided with guide bars or keys 68 for the reception of a plurality of rings or collars 62 which may be set in any adjusted position by means of set screws 64. These collars may be used to increase the width of the central web contacting portion 54 and the end contact portions 56 when a web 66, of greater width than the Web ID, is to be colored or marked. By providing a series of collars 62 of uniform width with a space 68, greater than the width of any one collar, between them, the bearing surface may be maintained at a maximum and adjusted to accommodate webs of any standard widths without permitting the line of contact between the pressure cylinder and the impression cylinder ever to overlap the edges of the web.

Usually the pressure or back-up cylinder is provided with an outside metal surface. However, in order to prevent scorching of the resilient impression cylinder at the points where the line of contact is interrupted, the bearing or contact surfaces of my improved pressure cylinder and the collars 62 may be provided with sheaths 10 of rubber or other suitable resilient material.

Although there are advantages in using the collars 62 on my improved pressure cylinder, it is to be understood that the first described construction shown in Fig. 1 will function efiiciently with webs considerably wider than the central web contacting portion 46. Moreover, if desired, the pressure cylinder may be constructed without any permanent central web contacting portion and such a contacting portion could be provided entirely by the slidable rings or collars. Various other changes may be made in the construction and certain features may be employed without others, without department from my invention or sacrificing any of its advantages.

What I claim is:

1. In a machine for marking webs of different widths, a marking cylinder wider than the web being marked; an impression cylinder wider than said web; and a pressure cylinder, substantially as wide as the impression cylinder, having a central web contacting portion which is no wider than the web.

2. In a machine for marking webs of different widths, the combination of a marking cylinder; an impression cylinder; and a back-up cylinder substantially as wide as the impression cylinder tral web contacting portion which is no wider than the web, and end contacting portions spaced from said central contacting portion and the edges of said web.

4. In a machine for marking webs of different widths, the combination with a marking cylinder and an impression cylinder wider than the Web being marked, of a pressure cylinder having a central web contacting portion, and means for adjusting said central web contacting portion so that the width thereof will correspond substantially with the width of the web.

5. In a machine for marking webs of different widths, the combination with a marking cylinder and an impression cylinder wider than the web being marked, of a pressure cylinder having a plurality of slidable collars mounted thereon and adapted to be adjusted to provide a central web contacting portion which is narrower than the web.

6. In a machine for marking webs of difierent widths, the combination with a marking cylinder and an impression cylinder wider than the web being marked, of a pressure cylinder comprising a central web contacting portion, portions of reduced cross sectional area on each side of said central contacting portion, and movable collars mounted on said reduced portions.

"I. In a machine for marking webs of difierent widths, the combination with a marking cylinder and an impression cylinder wider than the web being marked, of a pressure cylinder comprising a central web contacting 'portion, portions of reduced cross sectional area on each side of said central contacting portion, movable collars mounted on said reduced portions, and means for preventing movement of said movable collars with respect to said reduced portions.

8. In a machine for marking webs of different widths, a back-up cylinder having a centrally disposed web contacting portion which is no wider than the web and end contacting portions spaced from said web contacting portion for bearing against an impression cylinder at points beyond the edges of the web.

9. In a machine for marking webs of diiferent widths, a pair of spaced side frames; a marking cylinder wider than the web being marked and journalled in said side frames; an impression cylinder wider than said web and journalled in said side frames; and a pressure cylinder journalled in said side frames and having a central web contacting portion which is no wider than 25 the web.

ARTHUR M. WICKWIRE, JR. 

